Simon Pegg has opened up about his battles with alcoholism and depression, revealing that rehab helped turn his life around.

Speaking to The Guardian, the Star Trek and Mission: Impossible actor — soon to be seen in Mission: Impossible – Fallout — said that he had dealt with depression, which he’d suffered from since he was a teenager, through drinking. But this came to a head when he went to shoot 2006’s Mission: Impossible III in Los Angeles.

“When I watch that film back, I can see where I was then, which was fairly lost, and unhappy, and an alcoholic,” he admitted, describing the following half-decade as the "crisis years."

During this time, Pegg claimed he went AWOL for four days while promoting his 2011 comedy Paul at Comic-Con, and on his return to the U.K. found that he couldn't travel home without stopping for a drink.

"One thing [addiction] does is make you clever at not giving anything away," he said. "People think junkies and alcoholics are slovenly, unmotivated people. They're not — they are incredibly organized. They can nip out for a quick shot of whisky and you wouldn’t know they have gone. It’s as if…you are micro-managed by it."

But by this stage, Pegg said the signs were too obvious to his wife, and he "woke up in the Priory," a renowned medical facility in the U.K. that deals with alcoholism and addiction.

While he was being treated, he was forced to get court orders to prevent newspaper stories being published about his situation, the actor also revealed.

"They were sinking so low as to phoning up where I was and pretending to be my mother to get the story," he claimed. "I’m not ashamed of what happened. And I think if anyone finds any relationship to it, then it might motivate them to get well. But I am not proud of it either — I don’t think it’s cool, like I was Mr. Rock ’n’ Roll, blackout and all that s---. It wasn’t, it was just terrible."

Pegg’s rehabilitation coincided with the shooting of the sequel to Mission: Impossible III, 2011’s Mission: Impossible – Ghost Protocol, with the actor claiming that you can witness his improvement onscreen.

"We always laugh about it when we watch the movie," he said. "Try it! You’ll be like: ‘F---, he’s got cheekbones suddenly!’"

Related video: For more on Simon Pegg, watch below ... (via Popular Mechanics)